This absolute classic should need no introduction! But just in case...

Somewhere in the dark and nasty regions where nobody goes, stands an ancient castle. Deep within this dank and uninviting place lives Berk, overworked servant of the thing upstairs. But that's nothing compared to the horrors that lurk beneath The Trapdoor. For there is always something down there, in the dark, waiting to come out. Don't you open that Trapdoor. You're a fool if you dare! The Trap Door contains 40 episodes of the popular childrens series.